Power transistors commonly employed in automotive and industrial electronics require a low on-state resistance (Ron), while securing a high voltage blocking capability. For example, a MOS (“metal oxide semiconductor”) power transistor should be capable, depending upon application requirements to block drain to source voltages Vds of some tens to some hundreds or thousands of volts. MOS power transistors typically conduct very large currents which may be up to some hundreds of Amperes at typical gate-source voltages of about 2 to 20 V.
Power transistors usually include a body contact region that electrically contacts the body region to the source terminal. Thereby, a parasitic bipolar transistor is widely suppressed or deteriorated. Due to the body contact region, a pn diode is formed that results in a transistor having reverse blocking capabilities in one direction only.
Attempts are being made to provide semiconductor devices having further improved characteristics.